The present invention relates to medical technology, and more particularly to a method of manufacturing an implement for identifying patients at risk of developing diabetes-related foot problems.
Approximately 16,000,000 Americans are currently afflicted with diabetes, with another 800,000 new cases of the disease, on average, diagnosed among the American population each year. Both of these figures are expected to increase in the future, however, as there has been a 37% rise in the number of Americans diagnosed with diabetes in the last ten years.
Diabetes is a very serious disease, complications from which may lead to disabling conditions such as blindness, nerve damage and/or amputation, or to potentially fatal problems such as heart disease, stroke and/or kidney failure. Currently, diabetes is the seventh leading cause of death among Americans.
Among the factors that contribute to disabilities and/or fatalities within the diabetic population is the inability to either predict the occurrence, or to detect the onset of the complications which cause them. In many cases, symptoms of the onset of diabetic complications are undetectable. Furthermore, even in the instances where tests are available to accurately detect the onset of such complications, the tests are often painful, time-consuming and/or cost prohibitive to perform.
One notable exception, however, is a current test used to predict potential foot complications associated with diabetes.
Approximately 15-20% of the diabetic population will develop foot (i.e. plantar) ulcers during their lifetime due to diabetic neuropathy. And of the approximately 90,000 lower extremity amputations performed on the diabetic population each year, 85% are performed on those who had previously developed foot ulcerations. Moreover, approximately 50% of these amputees develop foot ulcers on their non-affected foot within eighteen months of amputation. Thus, the benefits of preventing foot ulcers among diabetics are abundantly clear.
The economic considerations of diabetic foot ulcerations are of increasing concern and continue to rise. Studies indicate that the cost of treating a diabetic foot ulcer can range from $1,929 to $6,664 and the cost for a lower extremity amputation can range from $20,248 to beyond $45,000. Fortunately, in 1992, a Lower Extremity Amputation Prevention (LEAP) program was developed by the Gillis W. Long Hansen Disease Center of Carville, La. (a division of the Bureau of Primary Health Care) to detect diabetic neuropathy and, consequently, to reduce the incidence of foot ulcers and resulting amputations among the diabetic population. The LEAP program includes five major components: annual foot screening; patient education; daily self-inspection of the feet; appropriate footwear selection; and management of simple foot problems.
At the foundation of the LEAP program is the foot screening component, which seeks to identify diabetics who have lost protective foot sensation. Between approximately 20% and 50% of individuals that have had diabetes for ten or more years will ultimately develop some form of peripheral sensory neuropathy. This affliction affects the bottoms (i.e., plantar aspect) of the feet, and manifests itself via a loss of sensation that begins in the toes and ultimately progresses back toward the heel.
To screen for loss of foot sensation among diabetics, a clinician tests a minimum of five plantar sites (see A, B, C, D, E in FIG. 1) on each foot of a patient by pressing a testing implement against each site until the testing device buckles, all-the-while monitoring whether the patient can detect the force created by the testing implement against his/her feet. A patient""s inability to detect sensation will signal to the tester that the patient is at high risk for plantar ulceration.
The testing process is quick, painless and inexpensive, but if done incorrectly, is entirely useless. For example, if not enough force is used, even a person with no loss of sensation will not be able to detect the pressure created by the testing device. By contrast, if too much force is used, a person with sensory loss will be able to detect the pressure created by the testing device despite his or her loss of sensation.
Tests have shown that such sensory diabetic foot screening/testing is best performed by using a nylon monofilament testing implement to apply ten grams of axial force to each of the five plantar test sites. Usage of such a device capable of producing this amount of force ensures a dependable method of assessment of the critical threshold of diabetic neuropathy and, in particular, whether or not there is a loss of protective sensation in the foot that could forecast the potential onset of plantar ulceration.
Of course, without some type of tool or gauge, accurate and consistent application of ten grams of axial force is practically impossible. Accordingly, a simple test device, known as a LEAP Testing Implement and shown in FIG. 2, was developed. In 1992 the original paper handled monofilament intended for diabetic foot screening was developed by the staff of the Gillis W. Long Hansen""s Disease Center located in Carville, La. to be utilized by the Lower Extremity Amputation Prevention Program developed and supported by the Health and Human Service/Bureau of Primary Health Care. This diabetic foot screening/testing device or LEAP testing Implement includes a 5.07/10 gram test element 2 that is attached to a handle element 4 such that the test element will deform when ten grams of force is applied axially to its free end (e.g., when applying force to a plantar site 6 as shown in FIG. 3).
For a LEAP Testing Implement to function properly (i.e., to have the test element deform at the correct force level) the test element 2 should lie at approximately a right angle, xcex1, with respect to the handle element 4 as shown in FIG. 2. Moreover, a specific length, L, of the test element that is equal to 38 millimeters plus or minus one millimeter should extend beyond the handle element 4. If this length is too short (i.e., is less than 37 millimeters in length), a greater force level will be required to deform the test element 2, and there arises a risk of false negative test results, while if the test element is too long (i.e., is greater than 39 millimeters in length), a lesser force level will deform it and could cause false positive results.
Because of the small length of the test element portion of LEAP Testing Implement, and the even smaller difference between an acceptable test element length and an unacceptable test element length, a mere visual inspection of a test element by the unaided eye and/or a comparison of the length of one test element to the length of another will not reveal whether a test element 2 portion of a LEAP Testing Implement is the proper length. As such, those who use LEAP Testing Implements as diagnostic tools must be assured that each Testing Implement was manufactured to exact specifications such that the test element portion 2 thereof has a length of between 37 millimeters and 39 millimeters extending from the handle element 4.
Presently, LEAP Testing Implements are manufactured by hand, wherein one or more individuals assembles each Testing Implement by placing a test element 2 at a specific point on an adhesive-coated handle element 4 and then folding a portion of the handle over the adhesive and part of the test element. Such an inexact manufacturing system is replete with opportunities for the production of unacceptable LEAP Testing Implements. Moreover, even if a LEAP Testing Implement assembler is somehow able to detect that he or she has made an unacceptable Testing Implement, it would be difficult, if not impossible, for him or her to reverse the assembly steps because, by the time the mistake is discovered, the adhesive would likely have already dried.
Not surprisingly, the Bureau of Primary Health Care has indicated that the rejection rate for such hand-assembled LEAP Testing Implements is generally in the range of 20% to 30%. Knowing this, manufacturers often employ measures in an effort to detect and remove unacceptable LEAP Testing Implements prior to their shipment to end users. This necessitates the hiring of extra personnel, which, in turn, translates into a price increase for the LEAP Testing Implements. Moreover, most believe that even with the addition of such detection measures, unacceptable Testing Implements are nevertheless being distributed to end users for testing.
Therefore, in view of the public good that can be obtained though the use of LEAP Testing Implements, a need exists for a method of manufacturing such Testing Implements in such a way as to guarantee both their quality and diagnostic accuracy, while not raising their cost of manufacture so much that the resulting device is rendered cost prohibitive to manufacture and/or use.
The present invention overcomes the disadvantages of hand fabrication of LEAP Testing Implements by providing a mechanical/automated method for their manufacture.
The method generally includes the steps of providing handle-forming and test element materials, scoring the handle-forming material, and then mechanically folding a first portion of the handle-forming material toward a second portion of the handle-forming material. The deformable test element material is then mechanically placed at a selected point between the first and second portions of the handle-forming material, after which the first and second handle-forming material portions are sealed together by machine components with the test element material therebetween. The handle-forming and test element materials are then mechanically cut to form the handle element and the test element of a LEAP Testing Implement.
In an exemplary aspect of the invention, the test element material is provided via a roll or spool and, prior to being sealed between the first and second portions of the handle-forming material, is heated at a predetermined temperature for a predetermined time in order to ensure the removal of any residual curvature thereof.
In an alternate aspect of the invention, the test element material, in lieu of being fed via a roll or spool, is instead fed in pre-cut lengths from a hopper feed mechanism.